Field experiments were conducted at four locations with the objectives to formulate and evaluate a new micronutrient fertilizer mixture and/or for the improvement of the existing mixture aiming at balanced fertilization to cotton. The experiments were conducted two locations of rainfed cotton at Aruppukottai, Kovilpatti (variety) and two locations of irrigated hybrid at coimbatore during 2010-11 in Randomized block design with six treatments replicated thrice. The treatments included the application of Farmers practice (T1), MN mixture of Department of Agriculture @ 7.5 kg/ha as straight chemical fertilizer (T2), NPK mixture at Recommended level (T3), TNAU MN mixture @ 15 kg/ha as straight chemical fertiliser (T4), TNAU MN mixture @ 7.5kg/ha as enriched FYM (T5), MN mixture of Department of Agriculture @ 7.5 kg/ha as EFYM (T6). The results revealed that rainfed cotton, the plant height and number of bolls per plant ranged from 37.7 to 53.2 and 11.4 to 18.8 respectively. Among the various treatments recommended dose of NPK with TNAU MN mix. @15 kg kg/ha as straight chemical fertilizer resulted in increased plant height and No .of bolls per plant which was on par with TNAU MN mix. @7.5 kg kg/ha as enriched farmyard manure, followed by Department of Agriculture MN mixture @ 7.5 kg as enriched farmyard manure. The highest cotton yield per hectare was registered in recommended dose of NPK with TNAU MN mix. @7.5 kg kg/ha as EFYM (567 kg) with B:C ratio of 1.45. The irrigated hybrid highest cotton yield per hectare was registered in recommended dose of NPK with TNAU MN mix. @ 15 kg kg/ha as EFYM (2267 kg) with B:C ratio of 2.6 followed by Increasing quantity of MN mixture @ 30 kg as staright chemical fertilizer which comparable with DoA MN Mixture @ 7.5 kg as EFYM (2059 kg). Hence, it is concluded that TNAU MN mixture @ 7.5 kg /ha as Enriched FYM for variety and 15 kg /ha as EFYM for irrigated hybrid was recommended for cotton to maximise yield with higher B: C ratio.

Keywords: Micronutrient mixture, mineral nutrient, Cotton, growth and kapas yield.